Aveva, down 1.2%, announced that its first half revenue improved 15% to £97.6m, while pre-tax profits rose 8% to £25.8m. The board increased the interim dividend to 4.5p from 4p.

CSR, down 1.8%, announced the details of its offer to return cash of up to £179m to its shareholders.

Blinkx jumped 5.9% and emerged as the top gainer in the Cambridge Index. The company announced an 84% surge in its first half revenues to £52m, while pre-tax profits rallied 66.7% to £1.57m. On the future outlook, the company expressed confidence for the rest of the financial year.

Brady, up 1.5%, announced that it would acquire Systems Alternatives International in a deal worth about £6.25m.

PDX fell 23.4%, emerging as the largest faller in the Cambridge Index, as the market reacted to news of changes to its board of directors and plans to raise about £6m for working capital requirements. The company announced the appointment of Hagen Gehringer as CEO, Paul Banner and Philip Corbishley as non executive directors and Bernie Bulkin as chairman.

Kier, down 6.4%, announced that it continues to be on course to meet its expectations for the current financial year, with much of this expected to come through towards the second half. However, the company added that the trading environment remains difficult, reflecting little sign of improvement in the UK construction market.

Cyan, unchanged at 0.8p, announced that it would issue 12,932,643 ordinary shares 0.5p, following the exercise of warrants. Ubisense, down 3.8%, launched a new mapping application called myWorld which leverages Google Maps and is aimed at helping business users get the most out of their spatial data.

In the UK, the FTSE 100 index closed 2.8% lower, at 5605.6, after the BoE downgraded its growth forecast and warned that the economy could remain below pre-financial crisis levels for the next three years. Dismal UK retail sales data also weighed on investor risk appetite.